Ar(3P0,2)+NH3初生态产物NH2(2A1)的内态分布

首次报告了在分子束条件下,研究Ar(3P0,2)+NH3碰撞解离反应·利用单光子计数方法进行测量,获得了部分转动分辨的初生态产物NH2(2A1)→（2B1）发射谱,并详细地进行了标识·发现主要为（0,v 2',0)→（0,0,0）跃迁（v2'≤5,K'a≤6,J'≤10)。通过对部分分辨较好的光谱范围进行了模拟,得到反应生成的NH2(2A1,v2'=2,k'a =1)态绕b/c轴的转动温度为1050K,高于母体分子NH3的转动温度300K。由亚稳态碰撞传能电子交换机理认为这是由于碰撞对手Ar和母体NH3分离时反冲作用的结果。碰撞传能解离机理和光解过程不同,后者仅观察到轴的转动激发。     

基于13X-APG的NH3和CO2同步吸附模拟

氨基甲酸铵发生分解/合成可逆化学反应过程中伴随显著的热效应,利用13X-APG沸石分子筛对NH3和CO2混合反应气吸/脱附行为移除/补充反应气来控制反应进行的方向和程度,从而通过控制反应吸/放热实现热量回收.本文采用实验结合模拟的方法探究13X-APG应用于NH3和CO2混合气体按反应比例实现同步吸附的性能,利用Mat...     

自由基分子NH2ν2带CO激光磁共振π谱的观测

采用高灵敏度、高分辨率激光磁共振光谱(LMR)方法在6μm谱段测量了自由基分子NH₂ν₂带的π谱(ΔM_J=0).测量了前人已测过的谱,结果与之较好符合.并观测到了前人没有观测过的新谱,在3支激光谱线下共获得约13支塞曼(Zeeman)跃迁谱线,其中在2支激光谱线下新测得的谱线10支.利用我们已经测得的^[8]σ谱的新的共振谱线的数值和已取得的激光磁共振谱线的标识方法,可预期得到NH₂的一些新的分子参数.     

The a2ν2 ← sν2 bands of 14NH3 and 15NH3

Numerous transitions belonging to the a2ν₂ ← sν₂ hot bands of ¹⁴NH₃ and ¹⁵NH₃ have been identified and assigned in the long-path Fourier transform spectra of ammonia. The data have been processed to obtain effective molecular parameters for the a2ν₂ states of ¹⁴NH₃ and ¹⁵NH₃.     

High-J transitions in the ν2 bands of 14NH3 and 15NH3

The Fourier transform spectra measured using the multiple reflection absorption cell with a path length of 192 m are reported for the high-J transitions of the ν₂ bands of ¹⁴NH₃ and ¹⁵NH₃. More than 400 transitions which have been assigned for the first time in both ¹⁴NH₃ and ¹⁵NH₃ represent nearly 100% extension of the ν₂ data.     

用色散荧光研究NH2（A^2A1）转动态—态传能

利用脉冲染料激光制备ＮＨ２（Ａ＾２Ａ１）单一转动能态Σ（０，９，０）３０３，在分子束条件下研究它的态－态转动传能至Σ（０，９，０）５０５，１０１和△（０，９，０）６２５，５２３，４２３，３２１，２２１各转动能态的相对截面。结果表明：转动跃迁│△Ｎ│＞２几率较小，│△Ｎ│愈小，传能截面愈大，而且同一电子振动态内传能最有效，且向下跃迁快于向上跃迁。分析荧光谱可以看出碰撞前后转动能极的对称性不变，这是单     

转动传能中NH2()精细结构态变化的研究

利用高分辨光谱技术他NH2（A~2A1,090)423(F1/F2) 在单次碰撞条件下的精细态色散光光谱,发现NH2（A~2A1)在与团壳层分子碰撞传能过程中,母能级的自旋－转动耦合守恒,从实验上直接证实了在开壳层－ 壳层分子碰撞过程中电子自旋为一旁观者的假设;由于长程作用力造成子能级有保持原来自旋－转动耦合的倾向。     

NH2自由基A^2A1,X^2B1电子振动能级结构及A^2A1～X^2B1 …

大振幅变曲振动哈密顿和矩阵变换变化,考虑Ｒｅｎｎｅｒ－Ｔｉｌｌｅｒ效应,计算了ＮＨ２自由基Ａ＾２Ａ１,Ｘ＾２Ｂ１态电子弯曲振动和Ｋ型转动能级。由计算得到的态函数和基态电偶极矩,计算ＮＨ２自由基Ａ＾２Ａ１～Ｘ＾２Ｂ１电子振动相对跃迁矩和电子激发态Ａ＾２Ａ１的荧光寿命,理论计算结果与」实验值符合较好。     

NH2自由基A~^2A1,X~^21电子态弯曲振动能级的理论计算

采用大振幅弯曲振动哈密顿,考虑到电子轨道角动量的Ｒｅｎｎｅｒ－Ｔｅｌｌｅｒ效应,从理论上计算了自由基ＮＨ２Ａ￣＾２Ａ１,Ｘ￣＾２Ｂ１电子态弯曲振动及其Ｋ型转动能级,计算结果在较大的能量范围内与实验数据符合较好。     

Stereodynamics and Rovibrational Effect for H＋NH3 →H2＋NH2 Reaction

We employ the semirigid vibrating rotor target (SVRT) model to study the influence of rotational and vibrational excitation of the reagent on reactivity for the reaction H NH3. The excitation of the pseudo H-NH2 stretching vibration of the SVRT model gives significant enhancement of reaction probability. Detailed study of the influence of initial rotational states on reaction probability shows strong steric effect. The steric effect of polyatomic reactions, treated by the SVRT model, is more complex and richer than theoretical calculations involving linear molecular models.     

NH3-H2O-LiBr吸收式制冷系统的可行性研究

针对目前氨水吸收式制冷系统的缺点由于高压侧(发生器和冷凝器)的工作压力过高带来的不安全隐患以及发生出来的气体中还有较多的水蒸汽而带来的系统过于庞大等问题,提出了相应的改进方案,在氨水系统中加入溴化锂,期望能够降低其工作压力以及气相中水蒸汽的含量。为了对该三元混合工质的可行性进行研究,在自行搭建的实验平台上,对其压力及温度进行了测试,测试温度范围从20℃到90℃,压力最高到2MPa,测试用溴化锂质量浓度范围从5%到60%。实验结果表明,与相同浓度下的氨水溶液相比,三元溶液的气液平衡压力降低了近30%～50%,气相中水蒸汽的含量最低可降到2.5%。实验结果为工业上的推广使用提供了理论依据。     

Rotational Spectra of CH3CCH–NH3, NCCCH–NH3, and NCCCH–OH2

Microwave spectra of NCCCH–NH₃, CH₃CCH–NH₃, and NCCCH–OH₂have been recorded using a pulsed-nozzle Fourier-transform microwave spectrometer. The complexes NCCCH–NH₃and CH₃CCH–NH₃are found to have symmetric-top structures with the acetylenic proton hydrogen bonded to the nitrogen of the NH₃. The data for CH₃CCH–NH₃are further consistent with free or nearly free internal rotation of the methyl top against the ammonia top. For NCCCH–OH₂, the acetylenic proton is hydrogen bonded to the oxygen of the water. The complex has a dynamicalC_2vstructure, as evidenced by the presence of two nuclear-spin modifications of the complex. The hydrogen bond lengths and hydrogen-bond stretching force constants are 2.212 Å and 10.8 N/m, 2.322 Å and 6.0 N/m, and 2.125 Å and 9.6 N/m for NCCCH–NH₃, CH₃CCH–NH₃, and NCCCH–OH₂, respectively. For the cyanoacetylene complexes, these bond lengths and force constants lie between the values for the related hydrogen cyanide and acetylene complexes of NH₃and H₂O. The NH₃bending and weak-bond stretching force constants for CH₃CCH–NH₃are less than those found in NCCCH–NH₃, NCH–NH₃, and HCCH–NH₃, suggesting that the hydrogen bonding interaction is particularly weak in CH₃CCH–NH₃. The weakness of this hydrogen bond is partially a consequence of the orientation of the monomer electric dipole moments in the complex. In CH₃CCH–NH₃the antialigned monomer dipole moments lead to a repulsive dipole–dipole interaction energy, while in NCH–NH₃and NCCCH–NH₃the aligned dipoles give an attraction interaction.     

Al_2O_3－SiO_2石油裂化催化剂上自由基空间分布的ESR成象

报道了用自己设计制作的电子自旋成象装置，对芳烃芳胺化合物在Ａｌ２Ｏ３－ＳｉＯ２催化剂表面酸中心所形成的正离子自由基进行二维ＥＳＲ成象研究．     

NH自由基与臭氧反应机理的理论研究

用量子化学从头计算方法,在HF／6－31＋＋G**水平研究了臭氧与NH三线态活性自由基反应的微观机理,优化得到反应物、过渡态、中间体和产物的几何构型。用MP2／6－31＋＋G**／／HF6－31＋＋G**方法计算能量,同时进行零点能校正。研究结果表明： NH三线态活性自由基与O3反应首先成稳定中间体NHO3,然后中裂解生成HNO和O2。     

Al2O3-SiO2石油裂化催化剂上自由基空间分布的ESR成象

报道了用自己设计制作的电子自旋成象装置,对芳烃芳胺化合物在Al₂O₃-SiO₂催化剂表面酸中心所形成的正离子自由基进行二维ESR成象研究.     

氨团簇(NH3)2的异构化研究

本文在密度泛函理论的基础上,利用B3LYP/6-31G(d)方法研究了(NH3)2的两种同分异构体2a和2b之间的异构化过程,结果表明由2a异构化到2b要跨过1.39kcal/mol的反应势垒,而从2b异构化到2a的反应势垒为0.606kcal/mol.     

Structural phase transition in a perovskite-type NH3(CH2)3NH3CuCl4 crystal – X-ray and optical studies

X-ray powder studies and optical studies (polarized microscopic observation and linear birefringence studies) of the crystal NH₃(CH₂)₃NH₃CuCl₄ are presented. The X-ray powder studies revealed a change of symmetry from orthorhombic room-temperature phase to monoclinic phase above 434 K. A reversible phase transition of the first order at 434 K on heating and 432 K on cooling was observed in birefringence studies. Optical polarized microscopic observation revealed monodomain and multidomain states in the room-temperature orthorhombic phase with domain walls in (110) and (1-10) planes. The hypothetical prototypic phase is expected to be tetragonal. The change of symmetry from orthorhombic to monoclinic and expected domain structure was found above 434 K in the (010) plane.     

NH++H2→NH2++H反应机理的量子力学研究

运用耦合簇理论CCSD方法对文献[1]提出的Titan大气中可能生成NH3的链式反应中第三个反应:NH H2→NH2 H进行了热化学计算和分析.发现:①反应(3)在Titan环境中具有良好的反应自发性,在低温下自发反应可能性更大.反应(3)的转变温度为11881.7 K,高于这个温度反应才不可能自发正向进行.运用量子化学MP2方法在6-311g(d)基组下计算研究了反应的机理,发现:②此反应分为两步反应,第一步为放热反应,无能垒.第二步反应的过渡态为平面构型.正反应能垒仅为38.991 Kcal.mol-1,完全可以由第一步反应放出能量来补偿.结果均经过振动分析和IRC计算验证.在不同温度下,尤其是低温下第一步反应平衡常数很大.③由于此反应有较高的反应自发性,可以认为该反应在这六个在Titan大气的低温环境中自然合成NH3的链式反应中起着积极的作用.④耦合簇理论方法和MP2理论两种方法的计算结果是一致的,互相印证了结论的可靠性.